Title:   Efficient query processing on XML streams 
Speaker: Yi Chen (Arizona State University)


Abstract:

Processing XML streams that can be potentially infinite and arrive
continuously is crucial for many applications, such as, monitoring stock
and sports tickers, traffic information, electronic personalized
newspapers, and entertainment delivery. However, evaluating XPath
queries in a streaming fashion needs to record a potentially exponential
number of pattern matches when both predicates and descendant axes are
present in queries, and the XML data is recursive. In this talk, I will
present the techniques to address this challenge by compactly encoding
these pattern matches and lazily probing the search space to validate a
query result. Our approach not only has a good theoretical complexity
bound but also is efficient in practice.  Finally I will discuss the
requirements and challenges of processing other types of queries over
XML streams, such as the ones that contain following axes, immediately
following axes, and their variants.


Short-Bio:

Yi Chen is an Assistant Professor in Computer Science & Engineering
(CSE) at Arizona State University.  She received her PhD from the
University of Pennsylvania in 2005. Her research interests include query
evaluation and optimization techniques for databases and streams, data
integration in presence of uncertainty and incompleteness, data model
and query language design, and scientific data management. For more
information, please refer to her home page
http://www.public.asu.edu/~ychen127/